Blue Green Chromis

The Blue Green Chromis is one of the most popular and widely kept marine aquarium fish, valued for its peaceful temperament, iridescent coloration, and natural schooling behavior. Unlike most damselfish species, which are notorious for territorial aggression, Chromis viridis is remarkably peaceful and makes an ideal community reef fish. Its body displays a gorgeous iridescent blue-green sheen that shifts and shimmers under aquarium lighting, creating a dazzling effect when a school of these fish moves in unison through the water column.

In the wild, Blue Green Chromis inhabit sheltered lagoons and reef flats throughout the Indo-Pacific, where they form large aggregations above branching Acropora corals. They retreat into the coral branches at the first sign of danger, using the intricate structure as protection from predators. This natural behavior can be replicated in the aquarium by providing branching coral or similar structures where the school can shelter. Groups of 5 or more individuals will display their most natural and visually appealing behavior.

While often recommended as a beginner's first marine fish, the Blue Green Chromis does have a commonly observed challenge: in small groups, a dominance hierarchy often develops in which the most dominant individual harasses subordinate fish, leading to gradual attrition of group members until only one or two remain. Starting with a larger group of 7 or more individuals in a spacious tank helps diffuse this aggression. Despite this social dynamic, the Blue Green Chromis remains one of the best schooling marine fish available, offering a slice of natural reef behavior that few other species can match. They are completely reef-safe, hardy, and accept virtually any aquarium food offered.